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ELECTRON MICROSCOPYOF ROTALIACEAN WALL STRUCTURES

HANS JØRGEN HANSEN AND ZEEV REISS

HANSEN, H. J. .& REISS, Z.: Electron microscopy of Rotaliaceanwall structures. Bull. geol. Soc. Denmark, vol. 20, pp. 329-346.Copenhagen, June 17th, 1971.

Representative species of the rotaliacean genera Ammonia, Pseudoro-talia, Pararotalia, Calcarina, Operculina, Elphidium, Cellanthus, Aste-rorotalia, and Rotalia were studied by aid of the scanning electronmicroscope. All were shown to build their primary chamber wallsaccording to the "bilamellar" pattern and to possess an inner liningand an outer lamella composed of stacked calcite platelets, and amedian layer composed of paired calcite crystals in an organicmatrix. The walls of all species examined are optically "radiate". AllRotaliacea possess a septal flap producing with the preceding septalface an interlocular space, which may be closed off partly at itsborder either primarily or by secondary lamination. Foraminal plates <extending from the flap are present in all genera mentioned, exceptin Rotalia. An umbilical coverplate extending from the foraminalplate into the previous chamber (where it is attached to the previousforaminal plate) occurs in Ammonia, Pseudorotalia, Pararotalia, Aste-rorotalia, and in the early ontogenetic stages of Calcarina. Secondarylamination covers exposed surfaces of earlier chambers, as well as thesides of the interlocular spaces where individual lamellae thin outconsiderably. Thinning out of secondary lamellae is also observed inthe electron microscope on the sides of ornamentational features whichare all inflational and produced by outer lamellae only. 121 scanningelectron micrographs illustrate the features described.

Since Smout's (1954, 1955) work, the Rotaliacea have been separated fromother groups of perforate and lamellar foraminiferids mainly by the presenceof a septal flap which was described as forming secondarily doubled septawith intraseptal passages communicating with a canal system. These featureswere believed to distinguish the "monolamellar" Rotaliacea from "bilamel-lar" groups, like e.g. the Orbitoidacea, where primary double septa andintraseptal passages without any true canal system were described (see Reiss,1963 and references therein). Lately, the true structure of the bilamellarwalls was clarified by Hansen, Reiss & Schneidermann (1969). They showedthat the so-called "passage" in bilamellar forms is in fact an organic medianlayer containing, at least in some genera, euhedral calcite crystals andseparating an outer lamella from an inner lining. This layer, therefore, can-

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330 HANSEN & REISS: Rotaliacean wall structures

not at all be compared with the true spaces formed between septal face andseptal flap in the Rotaliacea. Moreover, it was shown that in some bilamel-lar groups the inner lining does extend as a septal flap covering a previousseptal face (McGowran, 1966; Reiss & Schneidermann, 1969; Hansen, Reiss& Schneidermann, 1969). Finally, in thin sections of various rotaliaceans,examined under the light microscope, a kind of parting line within theprimary wall of the septal face in the final chamber can be observed andtraced over some distance. Such a parting line can be observed also in whatwas described as toothplates in such genera as Ammonia and Pseudorotalia.

In view of these findings the present authors examined by means ofscanning electron microscopy the wall structure of representative speciesbelonging to genera Rotalia, Pararotalia, Ammonia, Pseudorotalia, Astero-rotalia, Calcarina, Operculina, Elphidium and Cellanthus. The results of thedetailed ultrastructural study of these species lead also to a clarification ofcertain of their morphological features repeatedly discussed by variousauthors.

It should, however, be emphasized that the aim of the present paper is todescribe mainly the primary wall structure and only some of the moreimportant morphological features - which need clarification - of thegenera mentioned, and by no means a complete redescription of the latter.

The material studied originates from the A. Nørvang and J. Hofker col-lection from the Indopacific region, originally sampled by T. Mortensen anddeposited in the Mineralogical Museum of the University of Copenhagen,and from the micropalaeontological collection of the Department of Geology,The Hebrew University, Jerusalem. Special thanks are due to Prof. C. W.Drooger, Geological Institute, University of Utrecht, for putting at theauthors' disposal specimens of Rotalia trochidiformis from Grignon and ofspecies of Pararotalia described from the Aquitaine Basin.

The present work was made possible by a grant from the Rask-ØrstedFoundation to Z. Reiss and by the permission to use the equipment of theLaboratory of Electron Microscopy of the Geological Institutes of the Uni-versity of Copenhagen.

Thanks are due to lab.assistant Mrs. A. Nørgaard Jensen for able technicalassistance.

Part of the material studied was collected with the help of the MarineBiology Station of the Hebrew University in Elat.

Techniques

Both whole and fractured specimens, as well as half sections and thin sec-tions, etched or unetched, were examined in a "Stereoscan" Mk Ila scan-ning electron microscope. The preparation of the specimens for electron

Bulletin of the Geological Society of Denmark, vol. 20 [1971] 331

microscopy was made according to the methods described by Hansen (1968,1969) and by Hansen, Reiss & Schneidermann (1969).

The nearly 200 specimens studied and partly figured here are depositedin the collections of the Mineralogical Museum of the University of Copen-hagen, under registration number MMH no. 11164 (with subcode Rl -R153).

Ammonia beccarii (Linné)Since the characteristics of the rotaliacean wall structure are well repre-sented in the genus Ammonia, its type species, A. beccarii (Linné) will beconsidered first.

The primary chamber wall of Ammonia is composed of an inner and anouter layer, referred to here as the "inner lining" and the "outer lamella"respectively, and built of stacked calcite platelets. These two layers areseparated from each other by a very thin third layer, built of relatively largecalcite crystals, enveloped in organic material, arranged in pairs on bothsides of a thin, organic sheet. Adjacent pairs of crystals may touch eachother or they may be separated for a short distance, giving this third separat-ing layer a beaded appearance in section. This layer will be referred to hereas the "median layer" (pi. 1, figs 1-2).

The stacks of platelets composing the outer lamella and the inner liningare arranged normal to the median layer and to the test surface, althoughthe platelets themselves lie at an angle with them. The orientation of theplatelets within each individual stack remains generally constant. However,the platelets of each stack are seen in transverse section to be orientedwith respect to those of adjacent stacks at an angle of about 110°, thusproducing a "herringbone pattern" (pi. 1, fig. 2) ("chevron-shaped pattern"of Towe & Cifelli, 1967). Individual stacks of platelets may correspond tocrystal units as defined by Hansen (1970). Thin sections through the wallsof Ammonia examined under the optical microscope between crossed nicolsexhibit an extinction pattern indicative of the "radiate" wall-structure in thesense of Wood (1949). Within the limits of accuracy of the light microscopethe orientation of the c-axes of the platelets in the stacks is interpreted asnormal to the test surface.

In those instances where the angle between crystal faces could be measur-ed on electron micrographs of the median layer, it indicates a crystallo-graphical orientation with the c-axis normal to the test surface. The orienta-tion of the platelets in each stack appears to conform to that of a crystalface in the median layer (pi. 1, fig. 2).

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In both inner lining and outer lamella so-called primary lamination isobservable, marked by local changes in orientation and even size of theplatelets. In places, the outermost part of the outer lamella shows a structuredifferent from the stacked platelets: there, thin rod-like crystals about 0.3 julong occur, arranged normal to the test surface. This part of the wall (pi. 1,fig. 3) corresponds to the "veneer" described by Towe & Cifelli (1967). No.such veneer was observed in transverse sections through secondarily laminat-ed walls beyond the third or fourth outer lamella.

This structural pattern of the primary wall of Ammonia, i.e. inner lining,outer lamella, and median layer, is identical with that found in the "bilamel-lar" Cibicides lobatulus (Walker & Jacob). In the latter species, which isoptically radiate or indistinctly so, outer and inner layers are also composedof stacks of platelets in a herringbone pattern, and are separated from eachother by a median layer with paired calcite crystals (pi. 1, figs 4-6; pi. 2,fig. 1). On the other hand, in the bilamellar, but optically granulate genusHeterolepa, the median layer contains euhedral crystals, heterogenous insize, and which have not been observed to be arranged in pairs (pi. 2, fig.2). The outer and inner layers of this latter genus are also composed ofstacks of calcite platelets (Hansen, 1970; Hansen, Reiss & Schneidermann,1969). It may be noteworthy that walls constructed of stacks of calciticplatelets occur also in such radiate nodosariaceans as Lenticulina calcar(Linné) (Towe & Cifelli, 1967) and Lenticulina orbicularis (d'Orbigny)examined by the present authors (pi. 2, fig. 3). In these latter species, how-ever, the angle between adjacent stacks of platelets seems to be lower than ineither Ammonia or Cibicides, viz. about 75°.

The disposition of the different primary layers in the wall of Ammoniadiffers considerably in the various parts of the test.

The inner lining forms the lateral (spiral and umbilical) chamber walls,including the lip. Furthermore, the inner lining continues in order to form aposterior wall of the chamber, covering the septal face of the precedingchamber and being glued to it in places (pi. 2, figs 4-5). This is alwaysthe case along the foraminal border. This posterior wall is the "septal flap"of Smout (1954) and other authors. In those places where the septal flapis not glued to the previous septal face a space is formed, referred to earlieras "fissure" or "intraseptal passage", and considered here to be an inter-locular space in the sense of Reiss (1957). Thus, the "fissure" becomes infact a deeply sunken suture on the umbilical side. At the umbilical borderof the partly resorbed foramen, near the axial chamber wall (previous coil),the inner lining forms a plate-like extension, folded along an axis runningtowards the spiral side. This plate is glued to the umbilical wall of the adja-cent previous coil at its end near the spiral wall and appears in section as ahook-like structure. This plate is referred to here as the "foraminal plate"


and is present in all chambers, including the last formed one. It is in factpart of the "toothplate" of Hofker (1951), of Reiss & Merling (1958), ofReiss (1963), and of Ujiié (1965), as well as part of the "axial plate", aswell as the "apertural lip" as shown on plate 21 in Cifelli's (1962) paper.In addition to forming the septal flap and the foramina! plate, the innerlining extends from the foraminal plate into the previous chamber where itforms an umbilical "coverplate", glued to the axial wall (previous coil), tothe lip, as well as to the foraminal plate - below the fold - of that chamber.The coverplate leaves a communication open to the chamber interior cor-responding to part of the posterior labial aperture. The accompanying figures(pi. 2, fig. 6; pi. 3, figs 1-6; pi. 4, fig. 1) illustrate these features. Thecoverplate is in fact part of the "toothplate" of Hofker; Reiss & Merling;Reiss; and Ujiié (opp.cit.) and corresponds to part of the "axial plate"of Cifelli (1962). Chamber wall, septal flap, foraminal plate, and cover-plate in a previous chamber, are formed by the inner lining as one conti-nuous structure.

The outer lamella covers the inner lining in the septal and lateral chamberwalls, including the lip, as well as the septal flap wherever the latter is notglued to a previous septal face. Furthermore, the outer lamella covers theinner lining of the foraminal plate and of the coverplate. It covers outerlamellae of exposed earlier formed parts of the test, thereby producing thetypical "lamellar" pattern. The outer lamellae of consecutive chambers coverthe side walls of the interlocular spaces with secondary lamination. There,however, like on foraminal and coverplates, the individual outer lamellaebecome extremely thin in comparison with their thickness on lateral chamberwalls and at the bottom of the interlocular space (see pi. 4, figs 2-6; pi. 5,fig. 1). Since the consecutive outer lamellae forming the thin secondary lami-nation on the sides of the interlocular spaces are less than about 0.5^ thickthey are beyond the resolution of the light microscope, and for this reasonearlier workers were led to the belief that lamination is interrupted ("incis-ed") along the "fissure" (Smout, 1954, Reiss, 1963, etc.). All ornamenta-tional features, like pustules, granules, knobs, etc. are formed exclusivelyby local thickenings of the outer lamella and are further thickened secondari-ly by subsequent outer lamellae.

Whereever the outer lamella is in contact with the inner lining, the medianlayer separates them, thus enabling the observer to follow the distribution ofthe inner and outer layers as seen in section. The median layer was not foundto be present at the contact between outer and outer, or between inner andinner layers, and not present at the contact between an inner lining and theouter lamella of a preceding chamber. The latter case is clearly demonstratedin those parts of the test where the inner lining forms the septal flap andis glued to the preceding outer lamella (pi. 2, figs 4-5; pi. 5, fig. 1).


Except for the lip, only lateral chamber walls are perforate; all otherstructures mentioned lack pores. This is also true of all ornamentationalfeatures (Reiss, 1963). The organic pore-linings show a distinct constrictionboth at the junction with the median layer and at the boundaries betweenconsecutive secondary lamellae, where thin sheets of organic material arepresent (pi. 1, fig. 1; pi. 4, figs 5-6).

The imperforate septal face of A. beccarii bears rather small roundedpustules, as well as low, elongated ridges running from the interior marginalborder to the cameral edge (Reiss, 1963). At the junction between septalface and lateral wall, as well as between lateral wall and septal flap elongatedpustules, formed by local thickenings of the outer lamella, are present. Infla-tional knobs are present in the central umbilical area (pi. 5, figs 2-3, 5-6).In A. beccarii lips of consecutive chambers are fused near their umbilical tips(pi. 5, fig. 3). In A. batava (Hofker) the lips are shorter and are not fused attheir umbilical tips (pi. 5, figs 5-6). An inframarginal sulcus is present in thespecies of Ammonia examined, producing an infold of the apertural face atthe spiral end of the aperture (pi. 5, figs 3 and 6). No interlocular space isformed on the spiral side (pi. 5, fig. 4) between consecutive chambers. On theother hand, the inner lining is drawn inwards along the spiral suture, beingglued to the axial wall (former coil) some distance away from this suture.Thus, a very shallow interlocular space is formed along the spiral suture(pi. 5, fig. 6).

Pseudorotalia schroeteriana (Carpenter, Parker & Jones)The wall structure of this species (which is the type species of the genusPseudorotalia) is identical with that of Ammonia (pi. 6, figs. 1-4) and sois its basic morphology (pi. 6, fig. 5; pi. 7, figs 1-6; pi. 8, fig. 1).

Unlike in Ammonia, where no interlocular space is formed betweenconsecutive chambers on the spiral side, a deep interlocular space is presentin Pseudorotalia on both sides of the test. The septal flap is glued only tothe axial wall (previous coil) and to the former septal face along theforaminal border. At the edge of the septal face a string of imperforatepustules, formed by local thickenings of the outer lamella, is present in thenewly formed chamber at the junction between lateral wall and septal face,as well as between lateral wall and septal flap. These pustules are locallyrestricting, but not closing, the interlocular space (pi. 8, fig. 2). This situa-tion is very similar to that in Ammonia, where, however, the interlocularspace is broader, and the thickenings of adjacent chambers along this spaceare neither so strongly projecting, nor so near to each other.

In Pseudorotalia, with further secondary lamination, the opposing rows of

Bulletin of the Geological Society of Denmark, vol. 20 [1971] , 335

pustules along the edges of the interlocular space become more and morethickened until they coalesce completely after 3-4 instars, leaving roundedto oval communications open into the interlocular space (pi. 8, figs 3-4).These openings are the "canals" of Reiss & Merling (1958) and of Reiss(1963) as well as the "toothplate foramina" of Hofker (1968). This isunlike Ammonia where the rows of pustules do not meet. In Pseudorotalia,the coalescence may be regular, whereby bridges parallel to the peripheryare formed, with the sutural openings running in one line, or irregular,whereby bridges oblique to the sutures are formed with irregularly alternat-ing rows of openings in between.

Although only as a matter of degree, another difference between Ammoniaand Pseudorotalia may be noted, viz. the degree of distal folding of theforaminal plate which in Pseudorotalia is much stronger than in Ammonia(pi. 8, fig. 5).

Pararotalia

The following species of Pararotalia were -examined: P. inermis (Terquem)from the Lutetian of Grignon, France (type species of Pararotalia); P.mexicana mecatapecensis (Nuttall) from the Lower Miocene of Australia;P. calcar (d'Orbigny) from Recent sediments of the Gulf of Elat, Israel;Pararotalia sp. from the Oligocene of Gaas, France.

The wall structure could be observed in P. inermis and P. calcar only,while it was obscured by recrystallisation in the other species examined. Theoriginal wall structure of P. inermis and P. calcar is identical with that ofAmmonia and Pseudorotalia (pi. 8, fig. 6; pi. 9, fig. 1).

All the species of Pararotalia examined possess deep interlocular spaceson the umbilical side, formed by the septal flap and a preceding septal face;a rather slightly folded foraminal plate, extending from the septal flap andprotruding into the chamber (including the last formed one); an umbilicalcoverplate (Loeblich & Tappan, 1957) extending from the foraminal plateinto the preceding chamber and being attached there to the (preceding) for-aminal plate (pi. 9, figs 2-6; pi. 10, figs 1-3).

The aperture in all species examined is interio-marginally drawn out intothe apertural face in a kind of comma-shape. The distal border of theaperture is provided with thickenings forming an "apertural rim". The aper-tural face in the species examined is strongly pustulated, a feature which canalso be observed in section (pi. 10, fig. 4). In P. calcar and in P. mexicanaridge-like thickenings running obliquely from the suture line in peripheraldirection originate both from the junction septal face - lateral wall andfrom that of the lateral wall with the septal flap. They parallel roughly the


chamber form. At the periphery of P. calcar these ridges coalesce with theinflational, "feathery" spines of the chambers. Secondary lamination thick-ens the ridges, whereby the interlocular spaces are bridged over and cavitiesare trapped. These communicate with the outside through narrow canalsleading into the peripheral spines (pi. 10, figs 5-6).

Labial apertures are present in all species and they remain open after theformation of the coverplates (pi. 10, figs 3 and 5).

Calcarina spengleri (Gmelin)

Sections through the primary chamber wall of this species show the innerlining and the outer lamella, with the median layer between them, as in theother rotaliaceans mentioned. However, the platelets seem to be thickerthan e.g. in Ammonia or in Pseudorotalia (pi. 11, figs 1-3). Strong primarylamination is present in both outer and inner layers (pi. 11, fig. 2). Thecrystals in the median layer are not as prominent in Calcarina, since theplatelets of the adjacent layers of the primary wall are thicker and largerwith respect to the crystal pairs in the median layer as compared to otherrotaliaceans.

The apertures of adult chambers are multiple, rounded, interio-areal open-ings arranged in several rows. Each aperture is surrounded by a prominentcollar-like rim (pi. 11, figs 4-5). In the earlier chambers of the test thecamera! aperture appears to be single, and interio-marginal like in Pararotalia(pi. 11, fig. 6). When converted into foramina all apertures retain theiroriginal shape.

In the earlier parts of the test (in both mega- and microspheric forms) aforaminal plate is present, as well as a coverplate extending into a precedingchamber, again like in Pararotalia. In the adult chambers of the test, wheremultiple apertures occur, no coverplate is present any more and neither is adistinct foraminal plate recognizable, except a short forward extension of theseptal flap at the umbilical tip of the chambers.

The apertural face is imperforate and covered by prominent elongatedridges running from the interior margin in a general peripheral direction(pi. 12, fig. 1).

Elongated thickenings are present both on the anterior and on the po-sterior edges of the lateral chamber wall, running into a general peripheraldirection where part of them extends into the radial spines. The interlocularspace communicates with the exterior through openings left between incom-pletely coalescing thickenings of adjacent chambers. Canals also continueinto the complicated pathways of the inflational spines (pi. 12, figs 3 and5). As secondary lamination covers the test, intramural cavities are formed


(pi. 12, fig. 4). All ornamentational features are extremely complex, as canbe seen on the accompanying figures. The system of coalescense along thesuture line, as well as the "marginal cord"-like ridge-and-groove patternpresent in the spines and its communication with the interlocular spaces,are all strongly reminiscent of the construction of Operculina (see below).

Operculina sp.Specimens of Operculina collected in living state from the Gulf of Elat, wereexamined. Since the recent Operculina from the Gulf of Elat are at presentunder revision by Prof. L. Hottinger, Univ. of Basel, no species name isused here.

The wall structure of the specimens examined is identical with that of theother rotaliaceans described showing the herringbone pattern in both outerlamella and inner lining which are separated by the characteristically bead-ed, median layer. Both outer lamella and inner lining show primary lamina-tion (pi. 12, fig. 6; pi. 13, figs 1-3).

The apertures are multiple, an interio-areal row of rounded openingssurrounded by thickened rims (pi. 13, fig. 4). The apertural area is re-sorbed into an interio-marginal slit at the conversion of apertures into fora-mina (pi. 13, fig. 5). The septal face appears to be imperforate. It is coveredby elongated thickenings running in an anastomosing pattern from the baseof the septal face (interior margin) towards the periphery of the chamber(pi. 13, fig. 4) where they continue and form the islands of the "marginalcord".

Both at the junction between lateral wall and septal face, and betweenlateral wall and septal flap, rather irregular, imperforate, rounded thickeningsare present on the final chamber (pi. 13, fig. 6). With the addition of a newchamber the thickenings coalesce along the border of the interlocular spaceleaving very narrow and scattered openings (canals) as communications ofthe latter with the outside of the test (pi. 14, fig. 1). This situation is in factvery similar to that in Pseudorotalia where, however, the residual openingsare much larger. Unlike in Pseudorotalia no secondary lamination is presenton the walls of the interlocular space in Operculina (pi. 14, fig. 2); this maybe due to the relatively small size of the residual openings left in the latter.Secondary lamination thickens the island-like ridges of the marginal cord atthe periphery, being very thin on the sides of these ridges (pi. 14, fig. 3).The grooves between the ridges of the marginal cord communicate with theinterlocular spaces at the periphery. Moreover, scattered, radially directedcanals lead from the interlccular space into the secondarily thickenedmarginal cord (radial canals).


The septal flap is imperforate, glued to the ridges of the apertural face,and reflecting them in elongated corrugations (pi. 14, fig. 5). The actualspaces between flap and previous septal face are, therefore, elongated andnarrow (pi. 14, fig. 2). Rounded foramina are found scattered on the areaof the septal flap (pi. 14, fig. 5).

In each chamber, including the last formed one, two folded extensions ofthe septal flap are found at its interior margin on both sides of the(resorbed) foramen (pi. 13, fig. 5). They run towards the septal wall ofthe respective chamber with which they are fused and they are also glued tothe axial wall (former coil), together with which they form tube-like spaces(pi. 14, fig. 6). These plates appear in section as hook-like structures attach-ed to the previous coil (Reiss, 1963). Position and structural relationship ofthese folded plates indicate that they are foraminal plates. They correspondto part of the toothplates of Hof ker (see 1968) and to the toothplate ofReiss (1963) and other authors, while the spaces formed by them corre-spond to the so-called umbilical canals of authors. They seem to openfrontally. No umbilical coverplate extends into an earlier chamber, thusemphasizing the individuality of the foraminal plate.

Elphidium macellum (Fichtel & Moll)and Cellanthus craticulatus (Fichtel & Moll)The wall structure of the type species of Elphidium and Cellanthus (see Loeb-lich & Tappan, 1964) is identical with that of the other rotaliaceans describ-ed above. A columnar veneer has been observed in the outermost part ofthe outer lamella (pi. 15, figs 1-5; pi. 16, fig. 4). Both species are opti-cally "radiate" or indistinctly so (Wood, 1949; Krasheninnikov, 1960).Secondary lamination penetrates through the fossettes deeply into the inter-locular spaces, coating both walls in Elphidium and mainly the septal flapin Cellanthus:

The spines along the fossettes shown by Marszalek et al. (1969) are seenin section to be inflational features (pi. 15, fig. 4). Secondary laminationthins out strongly on the side-walls of the fossettes (pi. 15, fig. 4). It isabsent inside the retral processes (pi. 16, fig. 1). >

Lakeside-infilled preparations of Cellanthus show in vertical section the"umbilico-spiral canals" which are in fact the tubular spaces formed by theforaminal plates with the adjacent coil and opening frontally, like in Oper-culina (cf. Hofker; Reiss & Merling; Reiss, opp.cit., as well as Wade, 1957)(pi. 16, figs 2-3). These spaces lead into the "vertical canals" of thelaminated umbonal knobs. No coverplates are present. Spinöse projec-tions are found on the walls of the vertical canals, similar to those inthe fossettes (pi. 16, fig. 5).


Asterorotalia pulchella (d'Orbigny)Like in Ammonia and the other rotaliaceans described three layers composethe primary chamber wall of the type species o£ Asterorotalia, viz. an innerlining and an outer lamella exhibiting the characteristic herringbone patternof stacked platelets, and a beaded median layer in between (pi. 17, fig. 1).

The pustulated and imperforate septal face is strongly bent inward and' backward, particularly in the umbilical region where it joins a large, per-forate extension (lip?) of the umbilico-lateral chamber wall (pi. 17, figs2-3). This extension continues into a posterior and peripheral directionforming a "suprasutural" cover over most of the interlocular space on theumbilical side (pi. 17, fig. 4). The suprasutural extension (which is probablyhomologous with part of a lip, although it is largely perforate) is glued tothe former chamber, while its anterior part forms an elongated openingbetween itself and the wall of its own chamber, leading into the interlocularspace (pi. 17, fig. 5). The interlocular space is also present on the peripheryand for some distance on the spiral side, without being covered by theextension (pi. 17, fig. 4).

The cameral aperture is comma-shaped, interio-marginal and reminiscentof that in Pararotalia (pi. 17, figs 2 and 6). At the infold of the septal face(part of "lip" of Reiss & Merling, 1958; "toothplate" of Hofker, 1968) theaperture is strongly narrowed and may even become interio-areal (pi. 18,fig. 1). The apertural rim is strongly projecting and forms a kind of collararound the aperture (pi. 17, figs 2 and 6; pi. 18, fig. 1).

The septal flap is glued to the previous septal face only in that partwhich lies near the spiral side, as well as to the outer border of the foramen(pi. 18, fig. 2). Where the flap is not glued to the previous septal face awide interlocular space is formed (pi. 18, fig. 3).

The septal flap extends into a foraminal plate, which is distally stronglyfolded backwards, like in Pseudorotalia. The foraminal plate continues into anumbilical coverplate in the preceding chamber, where it is attached to theforaminal plate of that chamber (pi. 18, fig. 4).

The spines originate from the peripheral parts of the interlocular spaces;they are hollow and secondarily laminated (pi. 18, figs 4-5). Secondarylamination is present on the walls of the interlocular space also where it iscovered by the suprasutural extension (pi. 18, fig. 6).

Rotalia trochidiformis LamarckSpecimens of the type species of Rotalia from the type locality Grignon wereexamined. Despite the fact that diagenetic processes have affected most ofthe material, the herringbone arrangement of the platelets in both outer


lamella and inner lining can still be recognized, while the median, beadedlayer can be observed in places (pi. 19, figs 1-2). Like in all other rotalia-ceans mentioned, the pores of Rotalia are larger and more distinctly hexago-nal in outline on the inside of the primary chamber wall than on the outsidesurface, where they are smaller and rounded to oval in shape (pi. 19, fig. 3).

Despite its basically simple architecture, the morphology of the test ofRotalia appears highly complex in sections/This is due to chamber form andlip attachement.

A marginal prolongation and an inframarginal sulcus are present wherebythe septal face is strongly drawn backward between periphery and umbilicus(pi. 19, fig. 4). Along the interio-marginal aperture, near the periphery onthe umbilical side, the distal wall turns inward sharply with the sulcus,forming a deeply penetrating extension which is attached to the axial wall(adjacent previous coil) (pi. 19, fig. 5).

The posterior wall of the chambsr is formed by a septal flap which to-gether with the preceding septal face delimit a wide interlocular space (pi.19, fig. 6; pi. 20, fig. 1; pi. 21, figs 3-6).

Along the aperture a thickened rim is present extending into a broad,triangular, imperforate umbilical lip (pi. 19, fig. 4). This lip is usually fusedwith its umbilical tip both to the preceding lip of the same coil and to theinflational pustules in the umbilical area of the previous coil. Thus, ananterior and a posterior labial aperture are formed (Reiss & Merling, 1958;Reiss, 1963) (pi. 19, fig. 4; pi. 20, fig. 2; pi. 21, figs 2-3, 5-6). Almostat the border between septal face and lateral chamber wall the lip becomesseparated from the latter (pi. 19, figs 4 and 6; pi. 20, fig. 2; pi. 21, figs4-5). The lip is drawn out backwards towards the suture into a peripheraldirection becoming attached to the lateral wall of the respective chamber(pi. 19, fig. 6). The line of attachment runs from the border between lateralwall and septal flap in an oblique anterior direction. Both lateral chamberwall and lip are strongly curved inwards along this line of attachment (pi.20, fig. 3), thus forming what appears as the structure referred to as"astral furrow" or "toothplate" by various authors (cf. Davies, 1932, Reiss& Merling; Reiss, Hofker; Smout, opp.cit.). The attachment of the lip to thelateral chamber wall is, however, incomplete and an open umbilical, "labial"aperture is thus formed between them (Smout, 1954; Reiss & Merling,1958) (pi. 20, fig. 4; pi. 21, figs 1-6). The shape of chamber wall and lipalong the line of attachment produces the cornet-shaped infold described byDavies (opp. cit.) as the "puckering up" of the umbilical wall along the"astral lobe" (i.e. the lip).

The septal flap is attached to the preceding septal face along the borderof the (partially resorbed at its inner margin) foramen and to the spiral wallof the chamber. The axial wall of the chamber (former coil) is seen to be


largely covered by wall material of the respective chamber. This materialcoalesces with both the septal flap and the septal face of the same chamber(pi. 20, fig. 2). The state of preservation of the specimens examined pre-cludes a determination of the nature of the axial cover (inner lining?).

Neither a foraminal plate, nor a coverplate, like those found e.g. inAmmonia, occur in Rotalia.

The illusion of a toothplate is created particularly in sections by theshape of the septal wall (compare e.g. Neoeponides or Alabamina; Reiss,1960), as well as by the shape of lateral wall and lip at their attachment(pi. 20, fig. 5).

Imperforate, elongated thickenings occur both at the border betweenseptal face and lateral chamber wall, as well as between the latter and theseptal flap. Moreover, thickenings are present along the umbilical labialaperture and at the borders of the lip. These knobs and ridges are inflation-ally thickened by secondary lamination in later instars.

DiscussionAll species of rotaliaceans examined by the present authors possess the sameprimary wall structure, viz. an inner lining and an outer lamella composedof stacked calcite platelets, and in between a median layer composed ofpaired calcite crystals enveloped in organic material. While the inner liningforms the interior part of the chamber wall, the septal flap, the foraminalplate, and the coverplate (wherever present), the outer lamella coates theinner lining on exposed surfaces and wherever a connection with extralocularcytoplasm is possible. Furthermore, the outer lamella covers surfaces ofearlier formed chambers where such surfaces are in contact with extralocularcytoplasm, resulting in secondary lamination.

The wall structure of the rotaliaceans is, therefore, in principle identicalwith that of the "bilamellar" groups of foraminiferids, viz. Robertinacea,Globigerinacea, Orbitoidacea, Anomalinacea and Cassidulinacea (part)(Loeblich & Tappan, 1964).

While in these latter groups both optically radiate and granulate wallsbuilt of calcite platelets occur, as well as walls built of either morphologicallygranular calcite (optically radiate or granulate), or of prismatic aragonite allRotaliacea seem to have their inner lining and outer lamella composed ofstacks of calcite platelets which produce optically radiate extinction. The crys-tals of the median layer are paired in all rotaliaceans and in optically radiate,platy orbitoidacean genera, like Cibicides, but heterogenous in size, ratherirregularly distributed, and apparently not paired in such optically granulate,though platy, genera as Heterolepa. No crystals have hitherto been found in


the organic median layer of the planktonic Globigerinacea. The amount oforganic material in the median layer seems to be larger in bilamellar formsother than rotaliaceans, thus showing up in the former group more distinct-ly as a "dark line" in sections observed under the light microscope. Thisdifference in amount of organic material in the median layer is also evidentin the electron microscope, both transmission and scanning (compare Han-sen, Reiss & Schneidermann, 1969; Hansen, 1970).

The difference in wall structure between the rotaliaceans and other platy,optically, radiate, bilamellar foraminiferids is one of degree and not of kind.The Rotaliacea can be separated from other calcitic groups by the presence ofa septal flap, as proposed originally by Smout (1954). The victoriellids andtheir allies may have to be transferred again to the Rotaliacea (Loeblich &Tappan, 1964), although they possess a "murus reflectus", absent in therotaliaceans (Reiss, 1967). The bilamellar Robertinacea which possess aseptal flap are clearly separated from the Rotaliacea by their aragoniticwalls. The similarity between Rotaliacea and Robertinacea has been notedby Hofker and by Reiss (opp. cit.).

The interlocular space in the Rotaliacea seems to contain actively stream-ing, extralocular cytoplasm (cf. Reiss, 1963), as indicated by the thickeningsat its borders and formation of openings between these thickenings whereverthey coalesce, either primarily or secondarily; by the communication of thsinterlocular space with such structures as marginal cord, or inflational,canaliculate spines; by the formation of trapped intramural cavities commun-icating with the interlocular spaces; as well as by the thinning out ofsecondary lamellae within these spaces.

Whether or not the folded foraminal plate of the rotaliaceans is homo-logous with a true toothplate, like in the Buliminacea, remains questionable.It is certainly not characteristic of all rotaliaceans. An umbilical coverplatemay or may not be present in the Rotaliacea.

All ornamentational features are in fact inflational, imperforate and pro-duced by outer lamellae (Reiss, 1963). Thinning out of secondary lamina-tion, which can hardly be resolved under the light microscope, led to thebelief that these ornamentational features are in part incisional, in thesense of Smout (1954).

The present investigation clarifies certain confusing statements by earlierauthors concerning the morphology of the rotaliaceans studied and recon-ciles various divergent views on their structure.

The structure of Pararotalia as described by Loeblich & Tappan (1957)is confirmed, although the latter authors did not distinguish between for-aminal and umbilical coverplates (cf. also Ujiié, 1966). Cifelli's (1962) de-scription of the morphology of Ammonia is correct in showing the relation-


ship between foraminal and coverplates (collectively referred to by him asthe "axial plate"), but confuses (opp.cit., pi. 21) the foraminal plate with the"apertural lip". This latter description also erroneously states that theforaminal plate is absent in the final chamber and that the septa of Ammoniaare simple (cf. Wood, Haynes & Adams, 1963). Hofker; Reiss & Merling,and Reiss (opp.cit.) have evidently confused the foraminal plate in Am-monia, Pseudorotalia and Pararotalia with the coverplate extending into aprevious chamber and believed both structures to be formed within one andthe same chamber (cf. also Ujiié, 1965). However, these authors have cor-rectly recognized the relationship between foraminal plate and septal flap.Hofker; Reiss & Merling; and Reiss (opp.cit.) have erroneously describedtoothplates in Rotalia. Smout's (1954) emendation of Davies' description ofRotalia is correct; the confusing picture in thin sections of Rotalia is pro-duced by chamber form and by lip attachment. The symmetrical foraminalplates, producing the umbilico-spiral canals in Operculina, Elphidium andCellanthus were correctly described by Hofker and by Reiss (opp.cit.).

Rotalia is evidently a primitive form, since it possesses a septal flap onlyand no foraminal or coverplates; it resembles strongly certain Discorbidae.The relationship of Pararotalia to Calcarina is evident from the ontogeny ofthe latter genus (Hofker, opp.cit.). The phylogenetic relationships among theRotaliacea as proposed by various authors (Smout, 1955; Drooger, 1960;Reiss, 1963, etc.) still require a thourough investigation.

The classification within the suborder Rotaliina (all lamellar perforateforaminiferids) as proposed by Loeblich & Tappan (1964) can be largelyretained. The Discorbacea, the Anomalinacea and the Cassidulinacea re-quire, however, careful study with regard to their wall ultrastructure, viz.primary layering and the relationship between optical and ultrastructuralproperties of crystals building their tests. Representative genera of thesegroups are being investigated by the present authors.

The present investigation once more indicates - as pointed out earlierby Drooger (1954) and by Reiss (1963) - the difficulties in establishing ahierarchy of characters in the classification of the Foraminiferida.

AppendixAfter the completion of the present paper a galley-proof of S. Parvati'spublication "A study of some rotaliid foraminifera" was sent to Z. Reiss byProfessor C. W. Drooger. Although terminologies employed differ consider-ably, the morphological descriptions of Ammonia and Rotalia as given here


are largely in agreement with those given by Parvati. Such points of dis-agreement as e.g. Parvati's claim that the lamellae are not enveloping inAmmonia on the dorsal side is clarified by the present electron microscopicalstudy.

Dansk sammendragRepræsentanter for foraminifer-slægterne Ammonia, Pseudorotalia, Pararotalia, Cal-carina, Operculina, Elphidium, Cellanthus, Asterorotalia og Rotalia er blevet undersøgti scanning elektron mikroskop. Alle undersøgte former opbygger deres primære væggeefter det »bilamellære« princip. Væggenes ydre og indre lamel er opbygget af stakke aftynde calcitplader. Den ydre og indre lamel adskilles af et mellem-lag, der er dannetaf parrede calcit-krystaller, som ligger i en organisk matrix. Alle de undersøgte skal-ler er optisk radiate. Rotaliderne besidder en »septal flap«, som med det forudgåendeseptum danner et intercameralt rum, der kan være delvis tildækket — enten primærteller sekundært. Foraminale plader, der strækker sig i distal retning fra »septal flap«,er til stede i alle undersøgte slægter med undtagelse af Rotalia. Hos Ammonia, Pseu-dorotalia, Pararotalia og Asterorotalia, samt i tidlige ontogenetiske stadier hos Cal-carina, findes en umbilical dækplade, der strækker sig fra foraminal-pladen ind i detforudgående kammer, hvor den er fasthæftet til foraminal-pladen.

Sekundær laminering dækker alle blottede overflader af de forudgående kamre samtsiderne og bunden af de interloculære rum, hvor den dog bliver særdeles tynd. Påsiderne af ornamentale strukturer kunne ligeledes observeres aftagende tykkelse af desekundære lameller. Alle ornamentale strukturer er af den type som normalt omtalessom »inflational« og er udelukkende opbygget af ydre lameller.

Hans Jørgen HansenInstitut for historisk Geologi og Palæontologi,

Østervoldgade 5, DK-1350 København K, Denmark

Zeev Reiss .Department of Geology, The Hebrew University

Jerusalem, Israel

November 12th, 1970

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Unders. 42, 1-140.Cifelli, R. 1962: The morphology and structure of Ammonia beccarii (Linné). Contr.

Cushman Found, foram. Res. 13, 119-126.Davies, L. M. 1932: The genera Dictyoconoides Nuttall, Lockhartia nov. and Rotalia

Lamarck: Their type-species, generic differences, and fundamental distinction fromthe Dictyoconus group of forms. Royal Soc. Edinburgh, Trans. 57, 397-428.

Drooger, C. W. 1954: Remarks on the species concept in paleontology. The Micro-paleontologist S, 4 only.

Drooger, C. W. 1960: Some early rotaliid foraminifera I-III. Proc. Koninkl. Nederl.Akad. Wetensch. Ser. B. 63, 287-334.


Hansen, H. J. 1968: A technique for removing gold from plated calcareous micro-fossils. Micropaleontology 14, 499-500.

Hansen, H. J. 1969: Combined light and electron microscope studies of thin sections.Micropaleontology 15, 246 only.

Hansen, H. J. 1970: Electron-microscopical studies on the ultrastructures of someperforate calcitic radiate and granulate foraminifera. Biol. Medd. Dan. Vid. Selsk.17(2), 1-16.

Hansen, H. J., Reiss, Z. & Schneidermann, N. 1969: Ultramicrostructure of bilamellarwalls in foraminiferida. Rev. Espanola Micropal, l, 293-316.

Hof ker, J. 1951: The foraminifera of the Siboga Expedition. Siboga Expeditie. Mon.IV, (c), 3,514pp.

Hofker, J. 1960: The aperture of Pararotalia tuberculifera (Reuss). Natuurhist. Maandbl.Limburg 49, 79-83.

Hofker, J. 1963: Once again Pararotalia tuberculifera (Reuss). Naluurhist. Maandbl.Limburg 52, 80-82.

Hofker, J. 1968: Studies of foraminifera. Publ. Natuurh. Genoot. Limburg 18, 135 pp.Krasheninnikov, V. A. 1960: Mikrostruktura stenki u Miotsenovykh diskorbid i rotaliid.

Voprosy Mikropal. 3, 41—49.LeCalvez, Y. 1949: Revision des Foraminiféres Lutétiens du Bassin de Paris. II

Rotalüdae et families affines. Mem. Explic. Carte Géol. France, 1-54.Loeblich, A. R. & Tappan, H. 1957: Morphology and taxonomy of the foraminiferal

genus Pararotalia Le Calvez, 1949. Smithsonian Misc. Coll. 135 (2), 1-24.Loeblich, A. R. & Tappan, H. 1962: The status and type species of Calcarina, Tino-

porus and Eponides(Foraminiferida). Contr. Cushman Found, joram. Res. 13,33-38.Loeblich, A. R. & Tappan, H. 1964: Sarcodina chiefly "Thecamaebians" and Fora-

miniferida. In: Treatise on Invertebrate Paleontology (ed. R. C. Moore). Part C.Prostista 2, 1-900. Lawrence: Univ. of Kansas Press.

Marszalek, D. S., Wright, R. C. & Hay, W. W. 1969: Function of the test in fora-minifera. Trans. Gulf Coast Ass. geol. Soc. 19, 341-352.

McGowran, B. 1966: Bilamellar walls and septal flaps in the Robertinacea. Micro-paleontology 12, 477-488.

Reiss, Z. 1957: Notes on foraminifera from Israel, 5: Studies on Victoriellidae. Bull.geol. Surv. Israel 11, 1-9.

Reiss, Z. 1960: Structure of. so-called Eponides and some other rotaliiform foraminifera.Bull. geol. Siirv. Israel 29, 1-28.

Reiss, Z. 1963: Reclassification of perforate Foraminifera. Bull. geol. Surv. Israel 35,1-111.

Reiss, Z. 1967: Victoriella (Foraminiferida) from Israel. Israel J. Earth-Sci. 16, 111-119.Reiss, Z. & Merling, P. 1958: Structure of some Rotalüdae. Bull. geol. Surv. Israel 21,

1-19.Reiss, Z. & Schneidermann, N. 1969: Ultrastructure of Hoeglundina. Micropaleontology

15, 135-144. •Towe, K. M. & Cifelli, R. 1967: Wall ultrastructure in the calcareous foraminifera:

crystallographic aspects and a model for calcification. J. Paleont. 41, 742-762.Smout, A. H. 1954: Lower Tertiary foraminifera of the Qatar Peninsula. British Mus.

(Nat. Hist), London, 1-96.Smout, A. H. 1955: Reclassification of the Rotaliidea (Foraminifera) and two new

Cretaceous forms resembling Elphidium. J. Wash. Acad Sei. 45, 201-210.Ujiié, H. 1965: Shell structure of Japanese smaller foraminifera Part 1. Ammonia

tochigiensis (Uchio, 1951). Trans. Proc. Palaeont. Soc. Japan, N. S. 60, 156-165.

26 ' . •


Ujiié, H. 1966: Shell structure of Japanese smaller foraminifera part 2. Pararotalianipponica (Asano, 1936). Trans, f roc. Palaeont. Soc. Japan, N. S. 61, 191-200.

Wade, M. 1957: Morphology and taxonomy of the foraminiferal family Elphidiidae.J. Wash. Acad. Sei. 47, 330-339.

Wood, A., Haynes, J. & Adams, T. D. 1963: The structure of Ammonia beccarii(Linné). Contr. Cushman Found, joram. Res. 14, 156-157.

Wood, A. 1949: The structure of the wall of the test in the foraminifera; its value inclassification. Q. Jl geol. Soc. Land. 104, 229-255.

Plate 1Figs 1-3. Ammonia beccarii (Linné). Recent, Gulf of Elat, Israel.

1. Deeply etched section through wall of penultimate chamber showing orga-nic material of median layer intimately connected with organic pore-linings.(R-88). X 1050.

2. Horizontal section through part of septum showing arrays of platelets inouter lamella and inner lining, as well as the paired crystals in the medianlayer. (R-32). X 5620.

3. Vertical section through septum showing inner lining, outer lamella (thelatter with primary lamination), and the separating median layer. Noteveneer in outer lamella. (R-29). X 2970. .

Figs 4-6. Cibicides lobatulus (Walker & Jacob). Recent, Kattegat, Denmark.

4. Horizontal section through part of septum showing outer lamella andinner lining built of irregularly stacked platelets and pairer crystals in medianlayei. Very slightly etched. (R-l36). X 2250.

5. Horizontal section through outer wall of antepenultimate chamber show-ing inner lining, median layer and outer lamella covered by secondary lamina-lien (outer lamellae of two last chambers). (R-136). X 1500.

6. Oblique view of deeply etched section through septum showing the highconcentration of organic material in the median layer. (R-l 36). X 1500.

Abbrevaticns: /.- inner lining; o - outer lamella; m - median layer; v -veneer; p - primary lamination; s - secondary lamellae.

Bull. geol. Soc. Denmark, vol. 20, 1971, HANSEN & REISS Plate 1

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Plate 2Fig. 1. Cibiddes lobatulus (Walker & Jacob). Recent, Kattegat, Denmark.Horizontal section through septum showing furrow left in place of medianlayer where organic material and crystals have been tourn out. (R-136). X1500.

Fig. 2. Heterolepa cf. subhaidingeri (Parr). Recent, New Zealand. Horizon-tal section through part of septum showing outer lamella and inner liningcomposed of platy crystals, and large crystals enveloped in organic materialof the median layer. (R-137). X 3860.

Fig. 3. Lenticulina orbicularis (d'Orbigny). Recent, Kei Islands, PacificOcean. Horizontal section through secondarily laminated outer chamberwall showing consecutive outer lamellae built of stacked calcite plateletsproducing herringbone pattern. (R-63). X 4570.

Figs 4-6. Ammonia beccarii (Linné). Recent, Rimini, Italy.

4. Horizontal section through junction between final chamber with the pre-ceding one near test periphery and beginning of interlocular space. Notetermination of the median layer of last chamber and continuation of innerlining as septal flap, as well as its adherence to previous septal wall. (R-32).X 1610.

5. section like in fig. 4 in older part of the test and nearer the spiral side.Note secondary lamination. (R-32). X 1125.

6. Oblique umbilical view of fractured specimen showing foramen, foraminalplate and septal flap. (R-85). X 146.

Abbrevations: r - inner lining; o - outer lamella; m - median layer; s -secondary lamellae; fp - foraminal plate; sf septal flap; x — crystal in me-dian layer.

Plate 3Figs 1-6. Ammonia beccarii (Linné). Figs 1-2, specimen from Rimini,Italy; figs 3-6, specimens from Gulf of Elat, Israel.

1. Oblique umbilical view showing relationship between septal flap, for-aminal plate and coverplate. Note posterior labial aperture. (R-85). X 101.

2. Oblique umbilical view showing umbilical coverplate and posterior labialaperture. (R-85). X 207.

3-4. Horizontal section showing foraminal plates and their relationship toseptal flap and coverplate (fig. 4 detail of fig. 3). (R-116). Fig. 3, X 51;Fig. 4, X 161.

5-6. Horizontal section in umbilical region, passing through lips and labialapertures, as well as coverplates. (R-32). Fig. 5, X 112; fig. 6, X 442.

Abbrevations: la — umbilical labial aperture; cp — coverplate; sf — septalflap; ip - foraminal plate; / - lip.

Plate 4Figs 1-6. Ammonia beccarii (Linné). Gulf of Elat.

1. Detail of PL 3, fig. 5. Note median layer in lips and coverplates. (R-32).X788.

2. Vertical, partly tangential section showing interlocular spaces on um-bilical side and secondary lamination thinning out on the walls of the inter-locular space. (R-29). X 322.

3-4. Horizontal section through umbilical area showing secondary lamina-tion on foraminal and coverplates, as well as median layer in the latter.(R-32). Fig. 3, X 157; fig. 4, X 1490.

5. Horizontal section through secondarily laminated outer chamber wallshowing interlamellar organic sheets intimately connected with the organicpore linings. (R-88), X 2100.

6. Deeply etched horizontal section through secondarily laminated outerchamber wall. Note pore constrictions at lamellar boundaries. (R-32). X982.

Abbrevations: i - inner lining; o - outer lamella; m - median layer; s -secondary lamellae; cp - coverplate.

Plate 5Figs 1—4. Ammonia beccarii (Linné). Gulf of Elat, Israel.

1. Vertical section through septum near its junction with lateral spiral wallshowing disposition of various layers. Note continuity of outer lamellae ofconsecutive chambers. (R-29). X 825.

2-3. Oblique umbilical views of specimen with final chamber preserved.Note posterior labial aperture (in fig. 2), fusion of lips, interlocular spaces,inflational ridges, and pustules on imperforate septal face (in fig. 3).(R-35). Fig. 2, X 56; fig. 3, X 120.,

4. Oblique spiral view of last suture of specimen figured in figs 2-3. Notethe absence of interlocular space. (R-35). X 750.

Figs 5-6. Ammonia batava (Hofker). Recent, Kattegat, Denmark.

5. Oblique umbilical view of specimen with broken final chamber showingattachment of lip and labial aperture. (R-39)^ X 105.

6. Oblique umbilical view of same specimen as in fig. 5, showing aperturalinfold, the septal flap and foraminal plate, as well as the shallow, inter-locular space along the spiral suture. (R-39). X 105.

Abbrevations: i - inner lining; o - outer lamella; m - median layer; pi -primary lamination; is - interlocular space; sf — septal face; la - labialaperture; / - lip; ai - apertural infold; lia - lip attachment.


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Plate 6Figs 1-5. Pseudorotalia schroeteriana (Carpenter, Parker & Jones). Re-cent, Java.

1. Detail of section through perforate lateral chamber wall showing arrays ofplatelets and veneer in outer lamellae. (R-20). X 4120.

2. Detail of horizontal section through septum at bottom of interlocular-space, showing inner linings, outer lamellae and median layers of consecutivechambers (septal wall and septal flap), as well as secondary lamination, thin-ning out on the sides of the interlocular space and thickening towards its bot-tom. Note termination of median layer in septal flap at its junction with pre-ceding septal face. (R-18). X 525.

3. Part of horizontal section through a septum at its junction with secondari-ly laminated outer test wall, showing continuity of secondary lamellae overinterlocular space. (R-19). X 1240.

4. Section similar to that in fig. 3, showing thinning out of secondary la-mellae on the walls of the interlocular space. (R-19). X 405.

5. Horizontal section showing relationship between septal flap, foraminalplate, and coverplate. (R-94). X 32.

Abbrevations: o - outer lamella; v - veneer; i - inner lining; m - medianlayer.

Plate 7Figs 1-6. Pseudorotalia schroeteriana (Carpenter, Parker & Jones). Re-cent, Java.

1. Detail of pi. 6, fig. 5, showing relationship between septal flap, foraminalplate, and coverplate. (R-94). X 105.

2-3, 5. Horizontal section showing attachment of f oraminal and coverplates. Note termination of median layer in cover plate at point of attach-ment. (R-93). Fig. 2, X 28; fig. 3, X 252; fig. 5, X 709.

4. Strongly oblique horizontal section showing attachment of foraminal plateto axial wall (former coil) and succeeding coverplate. (R-89). X 788.

6. Oblique horizontal section showing relationship between septal flap,foraminal and coverplates at various levels of the test. (R-77). X 26.

Abbrevations: s — septum; sf — septal flap; fp — foraminal plate; cp —coverplate; / - inner lining; m - median layer.

Plate 8Figs 1-5.. Pseudorotalia schroeteriana (Carpenter, Parker & Jones). Re-cent, Java.

1. Vertical oblique section showing overlapping coverplates in successivechambers. Note foraminal plates. (R-72). X 31.

2. Outer view of imperforate inflational thickenings at margins of inter-locular space. Note coalescence in places. X 175. .

3-4. Details of horizontal section showing imperforate thickenings at mar-gins of interlocular space covered by secondary lamination. Note formationof residual openings and thinning out of secondary lamination at theirentrance. (R-19). Fig. 3, X 405; fig. 4, X 409.

5. Section through foraminal plate showing strong backward fold at distalend. Note median layer. (R-94). X 762.

Fig. 6. Pararotalia inermis (Terquem). Lutetian, Grignon, France. Detail ofhorizontal section through septum showing outer lamella and inner lining,as well as median layer, (R-114). X 5100.

Abbrevations: fp - foraminal plate; cp - coverplate; s - secondary lamellae;o — outer lamella; / — inner lining; m — median layer.

Plate 9Figs 1-5. Pararotalia calcar (d'Orbigny). Recent, Gulf of Elat, Israel.

1. Part of horizontal section through septum showing outer, inner and me-dian layers. (R-106). X 7980.

2-5. Horizontal section and details thereof showing relationship betweenseptal flap, foraminal plate, and coverplate, as well as presence of thickenedrim at outer border of foramen. (R-42). Fig. 2, X 89; fig. 3, X 630; fig. 4,X 300; fig. 5, X 559.

Fig. 6. Pararotalia inermis (Terquem). Lutetian, Grignon, France. Obliquehorizontal section showing foraminal and coverplates. (R-114). X 156.

Abbrevations: m - median layer; cp - coverplate; fp - foraminal plate;s - septum; t - thickening.

Bull. geol. Soc. Denmark, vol. 20, 1971. HANSEN & REISS Plate 9

5

27»

Plate 10Fig. 1. Pararotalia sp. Oligocene, Gaas, France. Horizontal section showingseptal flaps, foraminal plates and coverplates. (R-103). X 552.

Fig. 2. Pararotalia mexicana mecatapecensis (Nuttall). Lower Miocene,Australia. Horizontal section showing septal flaps, foraminal and cover-plates. (R-97). X 57.

Fig. 3. Pararotalia inermis (Terquem). Lutetian, Grignon, France. Obliqueumbilical view of specimen with broken final chamber showing attachmentof septal flap, the protruding foraminal plate, and the umbilical labialapertures. (R-4). X 98.

Figs 4-6. Pararotalia calcar (d'Orbigny). Recent, Gulf of Elat, Israel.

4. Profile view of specimen with final chamber intact. Note form of aperture.(R-3). X 36.

5. Umbilical view of same specimen as in fig. 4 showing elongated thicken-ings leading into the interlocular space, as well as peripheral spines. Noteresidual openings into interlocular space. (R-3). X 34.

6. Detail of horizontal section showing interlocular spaces, their communica-tions to the outside of the test and secondarily formed intramural cavities.(R-42). X 300.

Abbrevations: la - labial aperture; f p - foraminal plate; sf - septal flap;ro - residual openings.

Bull, geol Soc.Denmark, vol. 20, 1971. HANSEN & REISS Plate 10

Plate 11Figs 1-6. Calcarina spengleri (Gmelin). Recent, Mollucan Islands.

1. Detail of horizontal section through septum and its junction to outer wallshowing distribution of different layers. (R-55). X 1200.

2. Detail of horizontal section through septum showing relationship betweenseptal flap and preceding septal wall in area of adherence. Note herringbonepattern and primary lamination in septal flap. (R-55). X 3990.

3. Detail of horizontal section through outer wall showing inner lining,median layer, and outer lamella, as well as secondary outer lamella. (R-55).X 3990.

4. Oblique umbilico-apertural view of broken final chamber showing multipleforamina and their thickened rims. (R-l 26). X 207.

5. View of same specimen as in fig. 4, from behind showing the multipleforamina piercing the septal flap. (R-l26). X 225.

6. Detail of horizontal section through early ontogenetic stage of testshowing relationship between septal flap, foraminal plate and coverplate.(R-132). X 371.

Abbrevations: i - inner lining; o - outer lamella; m - median layer.

Plate 12Figs 1-5. Calcarina spengleri (Gmelin). Recent, Mollucan Islands.

1. Oblique apertural view of final chamber (partly damaged) showingmultiple aperture with thickened rims and elongated ridges on imperforate,finely pustulated apertural f ace. (R-l 27). X 112.

2. Umbilical view of specimen with preserved final chamber showing orna-mentational pattern along interlocular space and in peripheral region.(R-l 27). X 112.

3. View of canaliculate inflational spine showing anastomosing pathways anddelicate ridges along them on the thick ridges (compare with fig. 5). (R-l 27).X 157.

4. Detail of horizontal section showing intramural cavity trapped off bysecondary lamination. (R-55). X 1180.

5. Detail of horizontal section through secondarily laminated spine. (R-55).X 1610.

Fig. 6. Opercullna sp. Recent, Gulf of Elat, Israel (collected in living state).Detail of horizontal section through septum showing herringbone patternof calcite platelets. (R-30). X 9500.

Abbrevations: imc - intra mural cavity; s - secondary lamellae.

Bull, geol Soc.Denmark, vol. 20, 1971. HANSEN & REISS

mrPlate 12

Plate 13Figs 1-6. Operculina sp. Recent, Gulf of Elat, Israel (collected in livingstate).

1. Detail of horizontal section through septum showing paired crystals ofmedian layer. (R-24). X 3990.

2. Detail of horizontal section through septum showing empty space leftafter crystals and organic material have been removed. (R-24). X 3990.

3. Detail of vertical section through part of septum at its junction with thelateral chambsr wall showing disposition of various layers. Nots continuityof outer lamellae in secondarily laminated parts of the test. (R-30). X 2530.

4. Apertural view of final chamber showing multiple interio-areal aperturesand anastomosing thickenings on apertural face continuing into the marginalcord. (R-9). X 185.

5. Profile view of specimen with broken final chamber showing the septalflap and the symmetrical foraminal plates of this chamber. Note interio-mar-ginal resorbed foramen. (R-37). X 107.

6. Oblique profile view of final chamber showing irregular thickenings alongthe edge of the septal face. (R-9). X 400.

Abbrevations: i - inner lining; o - outer lamella; m median layer; s -secondary lamellae; sj - septal flap; f p - foraminal plate.

Plate 14Figs 1-6. Operculina sp. Recent, Gulf of Elat, Israel (collected in livingstate).

1. Detail of lateral view showing irregular coalescence of thickenings alonginterlocular space (last suture) and residual openings into the latter. (R-9).X 352.

2. Detail of horizontal section showing interlocular space subdivided byadherence of septal flap to ridges of septal face. (R-24). X 1390.

3. Detail of horizontal-tangential section through marginal cord showingpolygonal outline of "islands" which are secondarily laminated. (R-24).X 1380.

4. Detail of horizontal section at junction between septum and marginal cordshowing a vertical channel leading from interlocular space into cord. (R-53).X 945.

5. View of septal flap in final chamber showing corrugations caused byadherence of flap to ridges of previous septal face, as well as multiple arealforamina. (R-133). X 450.

6. Detail of horizontal section showing foraminal plates extending fromseptal flap and fused to septal face, as well as their anterior opening. (R-52).X 200.

Abbrevations: i - inner lining; o - outer lamella; m median layer; vc -vertical canal; af - areal foramen; f p - foraminal plate.

Bull, geol Soc.Denmark, vol. 20, 1971. HANSEN & REISS Plate 14

Plate 15Fig. 1. Elphidium macellum (Fichtel & Moll). Recent, off Napoli, Italy.Detail of horizontal section through outer wall near its junction with a sep-tum showing organic material of median layer after removal of the pairedcrystals, as well as herringbone pattern of platelets in outer lamella andinner lining. Note veneer of outer lamella. (R-109). X 10500.

Fig. 2. Cellanthus craticulatus (Fichtel & Moll). Recent, Mollucan Islands.Detail of horizontal section through septal flap showing inner lining, medianlayer with paired crystals and outer lamella covered by thin secondarylamellae. (R-59). X 3940.

Figs 3-4. Elphidium macellum (Fichtel & Moll). Recent, off Napoli, Italy.

3. Detail of horizontal section through tip of septum attached to previouscoil and showing disposition of various layers. (R-110). X 1935.

4. Oblique, tangential-horizontal section through secondarily laminated outerwall: of retral processes with fossettes between them. Note thinning out oflamination in fossettes and the presence of inflational spines in the latter.(R-110). X640.

Fig. 5. Cellanthus craticulatus (Fitchtel & Moll). Recent, Mollucan Islands.Detail of strongly oblique horizontal section through septum and its junctionto outer wall showing interlocular space and strong secondary lamination onseptal flap. Note structure of inflational pustules. (R-59). X 787.

Abbrevations: / - inner lining; o - outer lamella; m - median layer; v -veneer; s - secondary lamellae.

Plate 16Figs 1-5. Cellanthus craticulatus (Fichtel & Moll). Recent, Mollucan Is-lands.

1. Tangential-horizontal section of septum at its junction with lateral wallshowing secondary lamination in interlocular space and lack of secondarylamination inside the retral process. (R-59). X 1910.

2-3, 5. Vertical, very deeply etched section of specimen infilled with Lake-side showing vertical umbonal canals originating from "umbilico-spiral"canal. Note the thinning out of secondary lamellae in vertical umbonalcanal and impressions of spinöse projection of wall material near the outletof the canal. (R-134). Fig. 2, X 45; fig. 3, X 231; fig. 5, X 742.

4. Part of horizontal section showing disposition of primary and secondarylayers at bottom of interlocular space. Note secondarily laminated inflationalpustules. (R-59). X 1575.

Abbrevations: i - inner lining; o - outer lamella; m - median layer; s -secondary lamellae; is - interlocular space; r p - retral process; uc - um-bonal vertical canal; se - spiral canal.


28

Plate 17Figs 1-6. Asterorotalia pulchella (d'Orbigny). Recent, Siam Bay.

1. Detail of horizontal section through septum showing septal flap adheringto outer lamella, the latter is separated from the inner lining by the medianlayer with paired crystals. Note herringbone pattern. (R-66). X 3900.

2. Oblique apertural view of final chamber showing apertural rim and infoldof apertural face partly covered by umbilical chamber projection. (R-123).X 264.

3. Umbilical view of specimen showing suprasutural covers of interlocularspaces. (R-64). X 100.

4. Detail of fig. 3 showing termination of suprasutural cover near peripheryon umbilical side. (R-64). X 375.

5. Partial umbilical view of specimen showing openings along suprasuturalcovers. (R-123). X 314.

6. Apertural view of final chamber. Note shape of interio-marginal aperture,thickened rim and pustulate septal face, as well as infold and projection onumbilical side. (R-123). X 165.

Abbrevations: j - inner lining; o - outer lamella; m - median layer; ar -apertural rim; ai - apertural infold.

Plate 18Figs 1-6. Asteroratalia pulchella (d'Orbigny). Recent, Siam Bay.

1. Apertural view of specimen with interio-areal aperture and collar-likerim. (R-123). X 169.

2. View of penultimate chamber showing attachment of septal flap to pre-vious septal face, as well as the foraminal plate. (R-123). X 214.

3. Profile view of specimen with broken final chamber showing septal flappartly adhering to previous septal face and partly forming the interlocularspace, as well as the foraminal plate. (R-123). X 230.

4. Horizontal section showing foraminal plates and their relationship tocoverplates and septal flap. (R-65). X 189.

5. Detail of umbilical view of broken final chamber showing adherence ofchamber wall to spine originating from earlier interlocular space. (R-64).X 151.

6. Detail of vertical section showing secondary lamination on the sides andbottom of interlocular space under suprasutural cover. (R-135). X 150.

Abbrevations: sf — septal flap; fp - foraminal plate; is - interlocularspace; cp - coverplate; s — secondary lamellae.

Plate 19Figs 1-6. Rotalia trochidijormis (Lamarck). Lutetian, Grignon, France.

1. Detail of horizontal section through septal wall showing inner lining,outer lamella and median layer. (R-61). X 2250.

2. Detail of section through septum showing relict herringbone pattern ofcalcite platelets. (R-61). X 3780.

3. Detail of oblique, horizontal half-section showing polygonal outline ofpores on the inner wall surface. (R-61). X 1125.

4. Oblique umbilical view of specimen with final chamber preserved showingaperture, lip, posterior and anterior, as well as umbilical labial apertures. (R-125). X 127.

5. View of half-section showing inframarginal sulci and inward projectingextensions of apertural face. (R-61). X 47.

6. Oblique umbilical view of specimen showing attachment of lip in finalchamber and the posterior labial aperture. Note inflational ornamentationalong interlocular space and along umbilical labial aperture. (R-125). X 150.

Abbrevations: f - inner lining; o - outer lamella; m - median layer; a -aperture; / - lip; ula - umbilical labial aperture; pla - posterior labialaperture; ala ~ anterior labial aperture.


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Plate 20Figs 1-5. Rotalia trochidijormis (Lamarck). Lutetian, Grignon, France.

1. Horizontal section showing interlocular spaces and furrows between lipsand chambers. (R-61). X 40.

2. Umbilical view of broken specimen showing plastering of wall material onaxial chamber wall (previous coil), interlocular space and the umbilicallabial apertures. (R-96). X 114.

3. Detail of vertical half-section showing infold at line of attachment be-tween lip and chamber wall ("astral furrow"). (R-68). X 97.

4. Detail of umbilical view showing lip and umbilical labial aperture. (R-125). X 375.

5. Detail of vertical half-section showing illusion of a "toothplate" pro-duced by chamber shape. (R-68). X 75.

Abbrevations: is - interlocular space; ula - umbilical labial aperture; / -lip.

Bull. geol. Soc. Denmark, vol. 20, 1971. HANSEN & REISS

Plate 21Figs 1-6. Rotalia trochidiformis (Lamarck). Lutetian, Grignin, France.

1-5. Oblique umbilical and umbilical-peripheral views of broken specimenshowing position of lips, posterior, anterior and umbilical labial apertures,as well as septal flap, septal face and umbilical chamber wall. (R-153). Fig.1, X 58; fig. 2, X 95; fig. 3, X 190; fig. 4, X 190; fig. 5, X 190.

6. Oblique umbilical view of broken specimen showing secondary thickeningaround umbilical labial apertures. (R-154). X 98.

Abbrevations: I — lip; a/a - anterior labial aperture; ula - umbilicallabial aperture; uc — umbilical chamber wall; sf - septal flap; sw septalwall; pla - posterior labial aperture.

electron microscopy of rotaliacean wall structures2dgf.dk/xpdf/bull20-04-329-346.pdf · electron...

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